Questions

Resistivity :

Resistivity is a measure of the resistance to the flow of electrons. 

Conductivity :

Conductivity is just the inverse of resistivity, σ = 1/ρ, where σ is conductivity and ρ is resistivity.

Example:

Think of a pipe and water, the bigger the pipe, the easier water can flow and thus the lower the resistance. 

An eclipse happens when a planet or a moon gets in the way of the sun's light. Our planet Earth experiances two types of eclipses. They are Solar and Lunar eclipses.

Solar Eclipse : This occurs when The Sun, the Moon and the Earth are in a straight line. The moon being in middle blocks sun rays falling on the Earth.

Lunar Eclipse : The Sun, the Earth and the Moon are in a straight line. The Earth being in middle and moon in the shadow of Earth behind it.

Monopotassium tartarate was used in baking powder.

Accumulator register, Temporary register, Instruction register, Stack Pointer, Program Counter are the various registers in 8085

The main excretory organs of insects and spiders are Malpighian tubules.

Ans.  Suppose the speed of boat in still water is x km/h and speed of stream is y km/h

Speedof boat in downstream = (x + y) km/h x+ y = 32 …(i) 

Speed of boat in upstream = (x – y) km/h

x – y = 28 …(ii)

Add. Eqs. (i) and (ii), we get 2x = 60

x = 30 km/h